1 #include <string> 2 #include <iostream> 3 //查询性能最高 4 //允许重复的,hash_map 5 #include <unordered_map> 6 #include <algorithm> 7 using namespace std; 8 9 10 void main() 11 { 12 //允许重复的映射 13 unordered_multimap<string, double>mymap{ {"a1",113},{ "a2",143 },{ "a3",1123 } }; 14 15 mymap.insert(pair<string, double>("a4", 345)); 16 mymap.insert(pair<string, double>("a4", 315)); 17 mymap.insert(pair<string, double>("a4", 325)); 18 mymap.insert(pair<string, double>("a4", 335)); 19 20 /*mymap.insert(unordered_multimap<string, double>::value_type("a5", 3425));*/ 21 22 /*for (auto i : mymap) 23 { 24 cout << i.first << " " << i.second << endl; 25 }*/ 26 27 /*auto it = mymap.find("a1"); 28 if (it != mymap.end()) 29 { 30 cout << it->second << endl; 31 }*/ 32 33 //查找所有 34 auto it = mymap.equal_range("a4"); 35 36 for_each(it.first, it.second, [](unordered_multimap<string, double>::value_type &x) {cout << x.first << " " << x.second << endl; }); 37 cin.get(); 38 }